Abstract
Extensive ichthyological field survey conducted from 1996 to 2006 in the major rivers of Mizoram, Tripura and Barak drainage (in Assam and partly in Manipur) revealed the occurrence of bewildering diversity of fishes. Of these, the rivers in Mizoram revealed 42 species in river Tuirial, 42 species in river Kolodyne, 31 species in river Karnafuli, 25 species in river Mat, 36 species in river Tlawng, nine species in river Tuirini, 14 species in river Serlui and 23 species in river Tuivai. The rivers in Tripura reflected 28 species in Manu, 22 species in Khowai, 53 species in Gomati, and 22 species in Feni. In Barak drainage, river Barak portrayed 65 species (including collections from the proximity of its origin in Karong, Manipur), river Jatinga 61 species, river Sonai 54 species and river Dhaleswari 32 species. Declaration of ‘aquatic sanctuaries’ for the conservation of rare and endangered fishes like the mahseers have been strongly suggested in the paper.